A/J and C57BL/6J mice differ from each other with regard to several behaviors, including alcohol preference, open field activity, cricket killing, and rope climbing. A reversible yields C57 chimeras have shown ranges of behaviors including behaviors intermediate between those characteristic of A and C57 mice. They also show a concordance between alcohol preference and open field activity. We think this means that none of our behaviors is controlled by a clone or single cell, and that alcohol preference and open field activity are controlled by the same tissue. We propose to use the GPI electrophoretic mobility difference between the A and C57 strains to measure the A and C57 contribution to each tissue of our chimeras. This should give us an idea of which cell population controls each behavior. We propose also to complete development of 25 recombinant inbred lines derived from C57 and A mice. We will use these in order to 1) attempt to enumerate and to map the genes controlling our behaviors; 2) to ask whether alcohol preference and open field activity are controlled by the same genes as well as the same tissues. We propose also to develop a system, involving the mutant ichthyosis, for chimeric tissue analysis at the level of histological sections. Overall, we hope that these experiments will allow us to understand what tissues and what genes are involved in the expression of our several behaviors.